New MAISRC paper concludes VHS risk in Great Lakes region still high
The deadly disease Viral Hemorrhagic Septicemia virus will continue to be a threat for fish in the Great Lakes region, a new paper from MAISRC researchers Dr. Luis Escobar and Dr. Nick Phelps confirms. This paper builds upon previous MAISRC research, greatly expanding the scope beyond Minnesota and telling a broader, more complete story about VHS ecology and risk.
Escobar and his partners used a process called ecological niche modeling to predict which waterbodies are most at risk for the virus, taking into account daytime and nighttime temperature, precipitation, vegetation, bathymetry, solar radiation, and topographic wetness. Knowing the conditions that VHS can survive in, including its preferred temperatures, researchers were able to identify areas of high to low suitability for the virus.
They found that in much of the Great Lakes area, VHS virus has not yet reached "ecological equilibrium" – suggesting that there are still areas into which it can expand. In addition to the Great Lakes and inland lakes, rivers were also found to be suitable to support VHS. Infectious diseases like these in wild fish are a worrisome threat not only for biodiversity, but also for potential spillover to farmed fish.
Understanding what areas are at the highest risk for VHS occurrences is key for surveillance strategies, and can inform management plans for prevention and resource allocation. Going forward, researchers will expand and improve the model by including additional variables such as water flow, boater movement, baitfish and fish stocking, and river connectivity to understand the risk of VHS in Minnesota and beyond.
VHS is considered to be the most significant freshwater fish health threat in the world and can cause large-scale fish kills. It is transmitted fish-to-fish from close contact of contaminated water or reproduction. It is known to infect many popular game fish species such as Walleye, Muskellunge, Salmonids, and Bass. It has been confirmed in all of the Great Lakes but not yet detected in inland waters of Minnesota.
You can read the paper, Potential distribution of the viral hemorrhagic septicemia virus in the Great Lakes region, here.